settings: Improve visibility of "Enter Sends Message" setting.

Addresses user research feedback by duplicating the "Enter Sends
Message" setting in the Settings > Preferences menu, specifically within
the General section, ensuring users can easily locate and configure
this option.

server_events_dispatch: Remove break statement.
The settings page needs to be updated when
`enter_sends` property is updated.

css: Update vertical-align to middle for the checkbox element.

Co-authored-by: Akarsh Jain<akarsh.jain.790@gmail.com>.

web/src/server_events_dispatch.js

@@ -853,7 +853,6 @@ export function dispatch_normal_event(event) {
             }
             if (event.property === "enter_sends") {
                 user_settings.enter_sends = event.value;
-                break;
             }
             if (event.property === "presence_enabled") {
                 user_settings.presence_enabled = event.value;